2. The output of an OR gate is high (1) when: A. All inputs are low (0) B. At least one input is high (1) C. All inputs are high (1) D. At least one input is low (0) Answer: B. At least one input is high (1)
3. The output of a NOT gate is: A. The same as the input B. The complement of the input C. Always high (1) D. Always low (0) Answer: B. The complement of the input
4. The output of a NAND gate is high (1) when: A. All inputs are low (0) B. At least one input is low (0) C. All inputs are high (1) D. None of the above Answer: B. At least one input is low (0)
5. The output of a NOR gate is high (1) when: A. All inputs are low (0) B. At least one input is high (1) C. All inputs are high (1) D. None of the above Answer: A. All inputs are low (0)
6. The output of an XOR (exclusive OR) gate is high (1) when: A. The inputs are the same B. The inputs are different C. Both inputs are high (1) D. Both inputs are low (0) Answer: B. The inputs are different
7. The output of an XNOR gate is high (1) when: A. The inputs are different B. Both inputs are low (0) C. Both inputs are high (1) D. The inputs are the same Answer: D. The inputs are the same
Truth Tables
8. The truth table for a 2-input AND gate is:| A | B | Output |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
9. The truth table for a 2-input OR gate is:
| A | B | Output |
|---|---|---|
| 0 | 0 | 0 |
| 0 | 1 | 1 |
| 1 | 0 | 1 |
| 1 | 1 | 1 |
10. The truth table for a 2-input NOT gate is:
| A | Output |
|---|---|
| 0 | 1 |
| 1 | 0 |
11. A NAND gate is a combination of which two gates? A. OR and NOT B. AND and NOT C. NOR and OR D. XOR and XNOR Answer: B. AND and NOT
12. A NOR gate is a combination of which two gates? A. OR and NOT B. AND and NOT C. XOR and NOT D. NOT and XNOR Answer: A. OR and NOT
13. An XOR gate is often used in circuits that perform: A. Addition B. Subtraction C. Multiplication D. Division Answer: A. Addition
14. Which of the following gates is known as a universal gate? A. AND B. OR C. NOT D. NAND Answer: D. NAND
15. Which gate is commonly used for digital subtraction? A. AND B. OR C. XOR D. XNOR Answer: C. XOR
16. An XNOR gate is often used to check if two values are: A. Equal B. Greater C. Less D. Different Answer: A. Equal
17. What is the output of an XOR gate when both inputs are 0? A. 0 B. 1 C. Undefined D. 10 Answer: A. 0
18. In a 3-input AND gate, the output will be 1 only if: A. All three inputs are 0 B. At least two inputs are 1 C. All three inputs are 1 D. At least one input is 1 Answer: C. All three inputs are 1
19. Which of the following is the correct Boolean expression for the AND gate? A. A + B B. A • B C. A’ + B D. A’ • B Answer: B. A • B
20. Which of the following is the correct Boolean expression for the OR gate? A. A + B B. A • B C. A’ + B D. A’ • B Answer: A. A + B
21. The De Morgan’s law states that: A. (A + B)’ = A’ • B’ B. (A • B)’ = A’ + B’ C. Both A and B are correct D. None of the above Answer: C. Both A and B are correct
22. In a circuit with a NAND gate, what would be the output if both inputs are 1? A. 1 B. 0 C. Undefined D. Both 0 and 1 Answer: B. 0